Systems and methods for determining orthodontic treatment

ABSTRACT

Methods and systems for determining an orthodontic treatment for a patient are provided. The method comprises: receiving image data associated with a patient&#39;s skull; conducting, based on the image data, a cephalometric analysis of the patient&#39;s skull; identifying, via the cephalometric analysis, a first pair of reference points; identifying, via the cephalometric analysis, a second pair of reference points; generating based on the first and second pairs of reference points a first reference line and the second reference line, respectively; determining, based on an intersection of the first reference line and the second reference line, a rotation center of a patient&#39;s mandible; and based on the rotations center, determining the orthodontic treatment for the patient.

CROSS-REFERENCE

The present application is a continuation of U.S. patent applicationSer. No. 16/843,401 filed on Apr. 8, 2020, the entirety of which isincorporated by reference.

FIELD

The present technology relates to systems and methods for determining anorthodontic treatment for a patient, in general; and more specificallyto determining a rotation axis for a mandibular jaw of a patient fordetermining the orthodontic treatment.

BACKGROUND

For devising a new orthodontic treatment for a malocclusion disorder ofa patient (or for assessing efficacy of already an existent one) aimedat a specific malocclusion disorder of a patient, practitionerstypically use various anthropometric parameters associated with apatient's skull, determined through corresponding image data.

Some of these parameters may include those defining possible physicalspatial motion and positions of a mandibular jaw within the patient'sskull relative to his/her maxillary jaw, which are effectuated with anaid of his/her masticatories (chewing muscles). These specificparameters can be said to be indicative of articulation of the patient.

Specifically, considerations in assessing the articulation of thepatient may include estimating certain angles of the mandibular jaw, forexample, relative to the Frankfort horizontal plane associated with thepatient's skull while a mandibular head (also referred to herein as“mandibular condyle”) of the mandibular jaw is moving in a respectivetemporomandibular joint (TMJ), such as an incisal guidance angle, asagittal condylar angle, a Bennet angle, and the like. Accordingly, fora more accurate determination of these angles, it is first necessary toaccurately determine their vertex—a rotation center of the mandibularjaw, which is a geometric point in each respective mandibular head,through which a rotation axis of the mandibular jaw extends.

A more accurately determined rotation center of the mandibular jaw maythus allow a more realistic modelling of the articulation of themandibular jaw of the patient, which could further enable thedetermination of a more efficient and effective orthodontic treatmentplan (for example, through application of an orthodontic device orthrough surgery).

Certain prior art approaches have been proposed to address theabove-identified technical problem of determining the rotation center ofthe mandibular jaw as an intersection of specifically constructed linesusing image data associated with the patient's skull.

An article entitled “Location of the Mandibular Center of Autorotationin Maxillary Impaction Surgery”, written by Rekow et al., and publishedby American Journal of Orthodontics and Dentofacial Orthopedics in 1993discloses investigation focusing on the problems associated withlocating that center of autorotation and identifies factors that canincrease the probability of accurately identifying its location forpredicting surgical outcomes. The reliability of the Rouleaux techniquefor calculating the centers of rotation is established and is shown tobe acceptable, as long as the landmarks used for determining the centerare properly selected, and the magnitude of the rotation required issufficient. The location of the centers of autorotation of the mandiblesafter maxillary impaction surgery for 46 patients was used toinvestigate the errors associated with landmark selection and amounts ofrotation. Although there is much variation in its location, the centerdoes not lie within the body of the condyle but instead lies away fromthe condyle. Guidelines for maximizing the reliability of predictingsurgical outcomes on the basis of autorotation of the mandible aftermaxillary impaction surgery are given.

An article entitled “The Hinge-Axis Angle”, by Valinoti, and publishedby Journal of Clinical Orthodontics discloses constructing an anglearound the hinge-axis that goes through both condyles and is formed bythe intersection of two lines, the first being the Frankfort horizontalplane. The second line forming this angle is drawn from the condylecenters (the hinge axis passes approximately through these) to pogonion.The angle thus formed is Frankfort horizontal plane; hinge-axis point;hinge-axis pogonion line.

An article entitled “Prediction of Mandibular Autorotation”, by Nadjmiet al., and published by the American Association of Oral andMaxillofacial Surgeons discloses testing prospectively the hypothesisthat the center of mandibular rotation during initial jaw opening is thesame as during impaction surgery. If so, individual determination ofthis center would provide a simple method to predict the finalmorphology of the nasal tip, upper lip, lower lip, chin, andcervicomental profile. This would aid in deciding preoperatively whethernasal tip surgery, total mandibular surgery, a genioplasty, or submentalliposuction should complement the maxillary impaction procedure.

An article entitled “Prediction of Mandibular Movement and its Center ofRotation for Nonsurgical Correction of Anterior Open Bite via MaxillaryMolar Intrusion”, by Kim et al. discloses calculating center ofmandibular autorotation by measuring displacement of gonion (Go) andpogonion (Pog). Paired t-tests were used to compare variables, andlinear regression analysis was used to examine the relationship betweenAU6-PP and other variables.

U.S. Patent Application Publication No.: 2007/207441-A1 published onSep. 6, 2007, assigned to Great Lakes Orthodontics Ltd, and entitled“Four Dimensional Modeling of Jaw and Tooth Dynamics” discloses methodsand systems to digitally model the 4-dimensional dynamics ofjaw andtooth motion using time-based 3-dimensional data. Complete upper andlower digital models are registered to time-based 3-dimensionalintra-oral data to produce a true 4-dimensional model. Diagnostic andclinical applications include balancing the occlusion and characterizingthe geometry of the temporomandibular joint. The 4-dimensional model isreadily combined with conventional imaging methods such as CT to createa more complete virtual patient model.

SUMMARY

It is an object of the present technology to ameliorate at least some ofthe inconveniences present in the prior art.

The developers of the present technology have realized that the movementassociated with the mandibular jaw relative to the given patient'sFrankfort horizontal plane may be projected more realistically if therotation center of the mandibular jaw is determined as an intersectionof at least two reference lines generated based on an analysis of a 2Dlateral projection of the patient's skull.

Specifically, the developers of the present technology have appreciatedthat each of these at least two reference lines may be generated basedon a respective pair of reference points, identified in the lateralprojection of the patient's skull, that are indicative of muscleattachments of muscles involved in effectuating movements of thepatient's mandibular jaw, thereby accounting for individual features ofthe patient. In particular, developers have appreciated that accountingfor both rotational and translational components of mandibular jointmovement, through reference points relating to muscles used inrotational and translational movement, may contribute to modelling amore realistic movement.

Thus, the rotation center of the mandibular jaw determined as anintersection of the so generated lines may allow for modelling a morerealistic movement thereof. Particularly, certain non-limitingembodiments of the present technology may allow for determining therotation center of the mandibular jaw that is not located in the centerof the mandibular head, which may allow for effectively accounting forboth components of the mandibular movement—rotational and translational.

Further, using the 2D lateral projection of the patient's skull foridentifying the reference points and generating the lines allows for amore efficient, in terms of computational resources, method fordetermining the rotation center as there is no need for obtaining andfurther processing additional 3D scans (such as CT/magnetic resonancescans).

Accordingly, data of the rotation center of the mandibular jawdetermined according to the non-limiting embodiments of the presenttechnology is believed to help to determine a more efficient andeffective orthodontic treatment plan for the patient.

Therefore, according to one broad aspect of the present technology,there is provided a method for determining an orthodontic treatment fora patient. The method is executable by a processor. The methodcomprises: receiving image data associated with an image of a skull ofthe patient, the image data including data relating to a mandibularportion and a cranium portion of the skull; identifying, from the imagedata, a first pair of reference points for defining a first referenceline, the first pair of reference points including a first point on themandibular portion and a second point on the cranium portion of theskull of the patient; identifying, from the image data, a second pair ofreference points for defining a second reference line, the second pairof reference points including third and fourth points on the craniumportion of the skull; the second reference line intersecting with thefirst reference line; generating, based on the first pair of referencepoints, the first reference line; generating, based on the second pairof reference points, the second reference line; determining, based on anintersection of the first reference line and the second reference line,a rotation center for a patient's mandible; determining, based on therotation center of the patient's mandible, the orthodontic treatment forthe patient.

In some implementations of the method, the first point of the first pairof reference points comprises an Articulare point, and the second pointof the first pair of reference points comprises a Gnathion point.

In some implementations of the method, the third point of the secondpair of reference points comprises a Basion point, and the fourth pointof the second pair of reference points comprises an Orbitale point.

In some implementations of the method, the first point of the first pairof reference points comprises the Articulare point, the second point ofthe first pair of reference points comprises the Gnathion point, thethird point of the second pair of reference points comprises the Basionpoint, and the fourth point of the second pair of reference pointscomprises the Orbitale point.

In some implementations of the method, the identifying the first andsecond pairs of reference points comprises conducting a cephalometricanalysis of the image data.

In some implementations of the method, the cephalometric analysiscomprises processing the image data based on one or more of: imagesegmentation, image alignment, facial landmark detection, andpredetermined relative positions between anatomical landmarks.

In some implementations of the method, the image comprises one or moreof: a radiograph, a photograph, a CT scan, a dental model, and amagnetic resonance image.

In some implementations of the method, the image is a lateral image of afirst side of the skull of the patient.

In some implementations of the method, the rotation center is a firstrotation center of the first side of the skull of the patient, andwherein the method further comprises determining a second rotationcenter based on an image of a second side of the skull of the patient,and wherein the determining the orthodontic treatment is based on thefirst rotation and the second rotation center.

In some implementations of the method, the rotation center is not acenter of a mandibular head.

In some implementations of the method, the method further comprisessending instructions to display, on a screen, the image of at least aportion of the skull and including the rotation center of the mandible.

From another aspect, there is provided a method for generating avisualization of a skull of a patient including a rotation center of amandible, the method being executable by a processor, the methodcomprising: receiving image data, the image data being associated withan image of the skull of the patient, the image data including datarelating to a mandibular portion and a cranium portion of the skull;identifying, from the image data, a first pair of reference points fordefining a first reference line, the first pair of reference pointsincluding a first point on the mandibular portion and a second point onthe cranium portion of the skull of the patient; identifying, from theimage data, a second pair of reference points for defining a secondreference line, the second pair of reference points including a thirdand fourth points on the cranium portion of the skull; the secondreference line intersecting with the first reference line; generating,based on the first pair of reference points, the first reference line;generating, based on the second pair of reference points, the secondreference line; determining, based on an intersection of the firstreference line and the second reference line, a rotation center for apatient's mandible; sending instructions to display, on a screen, theimage of the skull including the rotation center for the patient'smandible.

According to another broad aspect of the present technology, there isprovided a system for determining an orthodontic treatment for apatient. The system comprises a computer system having a processor. Theprocessor is arranged to execute a method comprising: receiving imagedata associated with an image of a skull of the patient, the image dataincluding data relating to a mandibular portion and a cranium portion ofthe skull; identifying, from the image data, a first pair of referencepoints for defining a first reference line, the first pair of referencepoints including a first point on the mandibular portion and a secondpoint on the cranium portion of the skull of the patient; identifying,from the image data, a second pair of reference points for defining asecond reference line, the second pair of reference points includingthird and fourth points on the cranium portion of the skull; the secondreference line intersecting with the first reference line; generating,based on the first pair of reference points, the first reference line;generating, based on the second pair of reference points, the secondreference line; determining, based on an intersection of the firstreference line and the second reference line, a rotation center for apatient's mandible; determining, based on the rotation center of thepatient's mandible, the orthodontic treatment for the patient.

In some implementations of the system, the first point of the first pairof reference points comprises an Articulare point, and the second pointof the first pair of reference points comprises a Gnathion point.

In some implementations of the system, the third point of the secondpair of reference points comprises a Basion point, and the fourth pointof the second pair of reference points comprises an Orbitale point.

In some implementations of the system, the first point of the first pairof reference points comprises the Articulare point, the second point ofthe first pair of reference points comprises the Gnathion point, thethird point of the second pair of reference points comprises the Basionpoint, and the fourth point of the second pair of reference pointscomprises the Orbitale point.

In some implementations of the system, the identifying the first andsecond pairs of reference points comprises conducting a cephalometricanalysis of the image data.

In some implementations of the system, the cephalometric analysiscomprises processing the image data based on one or more of: imagesegmentation, image alignment, facial landmark detection, andpredetermined relative positions between anatomical landmarks.

In some implementations of the system, the image comprises one or moreof: a radiograph, a photograph, a CT scan, a dental model, and amagnetic resonance image.

In some implementations of the system, the image is a lateral image of afirst side of the skull of the patient.

In some implementations of the system, the rotation center is a firstrotation center of the first side of the skull of the patient, andwherein the system further comprises determining a second rotationcenter based on an image of a second side of the skull of the patient,and wherein the determining the orthodontic treatment is based on thefirst rotation and the second rotation center.

In some implementations of the system, the rotation center is not acenter of a mandibular head.

According to another aspect, there is provided a system for generating avisualization of a skull of a patient including a rotation center of amandible, the system comprising: a screen on which the visualization ofthe skull of the patient including the rotation center of the mandibleis displayed, and a processor connected to the screen and arranged toexecute, the method comprising: receiving image data, the image databeing associated with an image of a skull of the patient, the image dataincluding data relating to a mandibular portion and a cranium portion ofthe skull; identifying, from the image data, a first pair of referencepoints for defining a first reference line, the first pair of referencepoints including a first point on the mandibular portion and a secondpoint on the cranium portion of the skull of the patient; identifying,from the image data, a second pair of reference points for defining asecond reference line, the second pair of reference points including athird and fourth points on the cranium portion of the skull; the secondreference line intersecting with the first reference line; generating,based on the first pair of reference points, the first reference line;generating, based on the second pair of reference points, the secondreference line; determining, based on an intersection of the firstreference line and the second reference line, a rotation center for apatient's mandible; sending instructions to display, on a screen, theimage of the skull including the rotation center for the patient'smandible.

In the context of the present specification, unless expressly providedotherwise, a computer system may refer, but is not limited to, an“electronic device”, an “operation system”, a “system”, a“computer-based system”, a “controller unit”, a “control device” and/orany combination thereof appropriate to the relevant task at hand.

In the context of the present specification, unless expressly providedotherwise, the expression “computer-readable medium” and “memory” areintended to include media of any nature and kind whatsoever,non-limiting examples of which include RAM, ROM, disks (CD-ROMs, DVDs,floppy disks, hard disk drives, etc.), USB keys, flash memory cards,solid state-drives, and tape drives.

In the context of the present specification, a “database” is anystructured collection of data, irrespective of its particular structure,the database management software, or the computer hardware on which thedata is stored, implemented or otherwise rendered available for use. Adatabase may reside on the same hardware as the process that stores ormakes use of the information stored in the database or it may reside onseparate hardware, such as a dedicated server or plurality of servers.

In the context of the present specification, unless expressly providedotherwise, the words “first”, “second”, “third”, etc. have been used asadjectives only for the purpose of allowing for distinction between thenouns that they modify from one another, and not for the purpose ofdescribing any particular relationship between those nouns.

Embodiments of the present technology each have at least one of theabove-mentioned object and/or aspects, but do not necessarily have allof them. It should be understood that some aspects of the presenttechnology that have resulted from attempting to attain theabove-mentioned object may not satisfy this object and/or may satisfyother objects not specifically recited herein.

Additional and/or alternative features, aspects and advantages ofembodiments of the present technology will become apparent from thefollowing description, the accompanying drawings and the appendedclaims.

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of the present technology, as well as otheraspects and further features thereof, reference is made to the followingdescription which is to be used in conjunction with the accompanyingdrawings, where:

FIG. 1 depicts a perspective view of a 3D model of an upper arch formand a lower arch form of a subject, according to the non-limitingembodiments of the present technology.

FIGS. 2 to 4 depict schematic diagrams of example movements of amandibular jaw of the subject while performing a physiological functionassociated with opening his/her mouth, according to certain embodimentsof the present technology.

FIG. 5 depicts a schematic diagram of a system for determining anorthodontic treatment, according to certain embodiments of the presenttechnology.

FIG. 6 depicts a sematic diagram of a computing environment of thesystem of FIG. 5, according to certain embodiments of the presenttechnology.

FIG. 7 schematically depicts a lateral image of a first side of asubject's skull used, by a processor of the computing environment ofFIG. 6, for determining a rotation center of a subject's mandible,according to the non-limiting embodiments of the present technology.

FIG. 8 depicts a mandible model generated, by the processor of thecomputing environment of FIG. 6, based on the determined rotation centerfor determining the orthodontic treatment, according to the non-limitingembodiments of the present technology.

FIG. 9 depicts a flowchart of a method for determining the orthodontictreatment for the subject, according to the non-limiting embodiments ofthe present technology.

DETAILED DESCRIPTION

Certain aspects and embodiments of the present technology are directedto methods of and systems for determining movements of a mandibular jawof a patient in a TMJ indicative of patient's articulation, and further,based thereon, determining an orthodontic treatment plan for thepatient. According to the non-limiting embodiments of the presenttechnology, determining the treatment plan for the patient may furtherinclude, depending on a specific orthodontic problem of the patient,determining a new treatment plan, or determining a following stage oftreatment by dynamically assessing efficacy of a current treatment plan,for example.

Further, it should be expressly understood that, in the context of thepresent specification, the term “orthodontic treatment” is broadlyreferred to as any type of medical intervention aimed at correctingmalocclusions associated with the patient, including surgical andnon-surgical manipulations, such as, but not limited to, using aligners.Further, the orthodontic treatment, as referred to herein, may bedetermined by a professional practitioner in the field of dentistry(such as orthodontist, a maxillofacial surgeon, for example), orautomatically by a specific piece of software, based on respective imagedata and input parameters associated with the patient.

More specifically, certain aspects and embodiments of the presenttechnology comprise a computer-implemented method for determining arotation center of the mandibular jaw (also referred to herein as“mandible”) in an associated mandibular head (also referred to herein as“condylar head” and “mandibular condyle”) in the TMJ. Further, based onat least one so determined rotation center, a horizontal rotation axisof the mandible may be determined, which further defines certainmovements of the mandible.

Certain non-limiting embodiments of the present technology minimize,reduce or avoid some of the problems noted in association with the priorart. For example, by implementing certain embodiments of the presenttechnology in respect of the rotation center of the mandible, one ormore of the following advantages may be obtained: a more efficient andindividualized approach to determining mandibular movements on a 3Dmodel of patient's arch forms for determining the orthodontic treatmentplan for him/her. This is achieved in certain non-limiting embodimentsof the present technology by direct projecting so-determined rotationcenter and the rotation axis onto the 3D model of patient's arch formswithout taking additional 3D scans (such as computed tomography scans).In this regard, methods and systems provided herein, according tocertain non-limiting embodiments of the present technology, allowachieving a higher accuracy and stability in diagnostics ofmalocclusions, and consequently, devising more efficient and effectiveorthodontic treatment plans.

3D Model

Referring initially to FIG. 1, there is depicted a view of a 3D model100 representing a current configuration of an upper arch form 102 (alsoreferred to herein as “maxillary arch form”) and a lower arch form 104(also referred to herein as “mandibular arch form”) of a subject (alsoreferred to herein as “patient”, not depicted), in accordance with thenon-limiting embodiments of the present technology.

According to the non-limiting embodiments of the present technology, theupper arch form 102 comprises upper teeth 102 a and upper gum 102 b, andthe lower arch form 104 comprises lower teeth 104 a and lower gum 104 b.

It should be expressly understood that methods of obtaining the 3D model100 are not limited and may include, in certain non-limiting embodimentsof the present technology, computed tomography-based scanning of theupper arch forms 102 and lower arch form 104 of the subject, forexample, using a cone beam computed tomography (CBCT) scanner. Generallyspeaking, the CBCT scanner comprises software and hardware allowing forcapturing data using a cone-shaped X-ray beam by rotating around thesubject's head. This data may be used to reconstruct 3D representationsof the following regions of the subject's anatomy: dental (teeth andgum, for example); oral and maxillofacial region (mouth, jaws, andneck); and ears, nose, and throat (“ENT”). Accordingly, the CBCTscanner, depending on the task at hand, may allow not only for obtainingthe 3D representations of the upper arch from 102 and the lower archform 104, but also deeper bone structures, such as a maxilla and amandible of the subject respectively associated therewith, as well ascertain cranial structures, such as, for example, temporal bones and thetemporomandibular joints (TMJ).

In a specific non-limiting example, the CBCT scanner can be of one ofthe types available from 3Shape, Private Limited Company of HolmensKanal 7, 1060 Copenhagen, Denmark. It should be expressly understoodthat the CBCT scanner can be implemented in any other suitableequipment.

In other non-limiting embodiments of the present technology, the 3Dmodel 100 may be obtained via intraoral scanning, by applying anintraoral scanner, enabling to capture direct optical impressions of theupper arch form 102 and the lower arch form 104.

In a specific non-limiting example, the intraoral scanner can be of oneof the types available from MEDIT, corp. of 23 Goryeodae-ro 22-gil,Seongbuk-gu, Seoul, Korea. It should be expressly understood that theintraoral scanner can be implemented in any other suitable equipment.

In yet other non-limiting embodiments of the present technology, the 3Dmodel 100 may be obtained via scanning molds representing the upper archfrom 102 and the lower arch form 104. In this regard, the molds may havebeen obtained via dental impression using a material (such as a polymer,e.g. polyvinyl-siloxane) having been imprinted with the shape of theintraoral anatomy it has been applied to. In the dental impression, aflowable mixture (i.e., dental stone powder mixed with a liquid incertain proportions) may be flowed such that it may, once dried andhardened, form the replica. The replica may then be retrieved from thedental impression and digitized by a desktop scanner to generate the 3Dmodel 100.

In a specific non-limiting example, the desktop scanner can be of one ofthe types available from Dental Wings, Inc. of 2251, ave Letourneux,Montreal (QC), Canada, H1V 2N9. It should be expressly understood thatthe desktop scanner can be implemented in any other suitable equipment.

According to the non-limiting embodiments of the present technology, the3D model 100 is used for determining an orthodontic treatment for thesubject. In this regard, according to the non-limiting embodiments ofthe present technology, the orthodontic treatment may be determinedbased on data indicative of how the lower arch form 104 moves relativeto the upper arch form 102; specifically, as an example, how the lowerteeth 104 a move relative to the upper teeth 102 a. In a sense, thesemovements may, at least partially, define articulation of the mandibleof the subject (such as a mandible 204 depicted in FIG. 2).

In the context of the present specification the term “articulation” isbroadly referred to as all possible physical spatial movements of themandible 204 relative to a maxilla of the subject (such as a maxilla 202depicted in FIG. 2), and effectuated by respective masticatories whenthe subject is involving the mandible 204 in implementing aphysiological function, such as speaking or eating, for example, orotherwise moving the mandible 204. Examples of such movements include,without being limited to, rotational movements of the mandible 204,translational movements of the mandible 204, and transverse movements ofthe mandible 204 in various planes of a subject's skull (such as a skull200 depicted in FIG. 2).

Mandible Articulation

Generally speaking, when the mandible 204 of the subject is involved inimplementing one or more physiological functions, the mandible 204 mayperform several movements, in one or more planes of the skull 200,simultaneously, depending on a specific phase of performing thephysiological function. This may result in a total movement of themandible 204 being very complex. Thus, for illustrative purposes only,below are provided examples in respect of translational and rotationalmovements of the mandible 204 in a sagittal plane of the skull 200.

With reference to FIGS. 2 to 4, there is schematically depicted thesagittal plane of the skull 200 of the subject for demonstrating certainmovements of the mandible 204 defining, at least partially, thearticulation thereof when the subject is opening his/her mouth, inaccordance with the non-limiting embodiments of the present technology.

Broadly speaking, the skull 200 comprises a cranial portion 201 (thatis, an unmovable portion thereof) and the mandible 204 (that is, amovable portion thereof). The cranial portion 201 further comprises themaxilla 202 with the upper teeth 102 a. The mandible 204 furthercomprises the lower teeth 104 a and a mandibular head 206. Generallyspeaking, movements of the mandible 204 relative to the maxilla 202 areenabled by a TMJ 208.

With reference to FIG. 2, there is depicted a schematic diagram of themandibular head 206 performing a translational movement in the TMJ 208.For example, the translational movement of the mandibular head 206occurs when lower anterior teeth of the lower teeth 104 a are slidingdown internal surface of upper anterior teeth of the upper teeth 102 auntil they reach a position of being edge to edge to each otherproducing a temporary underbite 212. Typically, this translationalmovement, in the sagittal plane of the skull 200, occurs when thesubject is starting opening his/her mouth and results in the mandible204 moving translationally in a first translation direction 210.

With reference to FIG. 3, there is depicted a schematic diagram of themandibular head 206 performing a pure rotational movement (also referredto herein as “hinge movement”) in the TMJ 208. For example, the hingemovement of the mandibular head 206 may occur during a phase where thesubject is continuing opening his/her mouth until the anterior teeth ofthe upper teeth 102 a and the lower teeth 104 a are around 20 to 25 mmapart in certain subjects.

Consequently, the mandible 204 performs, in the sagittal plane of theskull 200, a rotational movement in a first rotation direction 302around an axis extending through a geometric center 306 of themandibular head 206 and parallel to a horizontal plane 308 of the skull200.

However, when the subject is continuing opening his/her mouth to itsmaximum, where the anterior teeth of the upper teeth 102 a and the lowerteeth 104 a are around 43 to 50 mm apart in certain subjects, a movementof the mandibular head 206 in the TMJ 208 during this phase mayrepresent a superposition of rotational and translational movements.With reference to FIG. 4, there is depicted a schematic diagram of thesubject opening its mouth to its maximum, which causes the mandibularhead 206 to move, in the TMJ 208, rotationally downwards andtranslationally forwards. This movement of the mandibular head 206 isindicative of the mandible 204 moving downwards and backwards asindicated by a second rotation direction 402 and a second translationdirection 404. Thus, it can be said that, in this phase of opening themouth, for example, the mandible 204 performs, in the sagittal plane ofthe skull 200, a rotational movement around an axis extending through arotation center 406 that is shifted from the geometric center 306 of themandibular head 206.

Accordingly, the non-limiting embodiments of the present technology aredirected to methods and systems for determining the rotation center 406,and hence the rotation axis determined based thereon, in the mandibularhead 206 effectively accounting for rotational and translationalmovements of the mandibular head 206 in the TMJ 208.

Further, referring back to FIG. 1, according to the non-limitingembodiments of the present technology, the determined rotation center406 and the rotation axis for the mandible 204 may be used forreproducing (in a sense, “animating” or modelling) movement of the lowerarch form 104 relative to the upper arch form 102, thereby transferringthe articulation movements of the mandible 204 onto the lower arch form104.

Finally, according to the non-limiting embodiments of the presenttechnology, the so reproduced movements of the lower arch form 104relative to the upper arch form 102 may be used for determining theorthodontic treatment for the subject. For example, the reproducedmovements of the lower arch form 104 may be used for determining certaindiagnostic parameters, such as angles formed by the mandible 204relative to a Frankfort horizontal plane associated with the skull200(not separately depicted) associated with the subject, including, butnot being limited to, an incisal guidance angle, a sagittal condylarangle, a Bennet angle, and the like. Certain discrepancies of currentvalues of these angles from their normal values may be indicative ofspecific malocclusion disorders, for treating which respectiveorthodontic treatment plans can be determined. How the rotation center406 of the mandible 204 is determined will be described below withreferences to FIGS. 7 to 9.

System

Now, with reference to FIGS. 5 to 6, there is depicted a schematicdiagram of a system 500 suitable for determining the orthodontictreatment for the subject based on the rotation center 406, inaccordance with the non-limiting embodiments of the present technology.

It is to be expressly understood that the system 500 as depicted ismerely an illustrative implementation of the present technology. Thus,the description thereof that follows is intended to be only adescription of illustrative examples of the present technology. Thisdescription is not intended to define the scope or set forth the boundsof the present technology. In some cases, what is believed to be helpfulexamples of modifications to the system 500 may also be set forth below.This is done merely as an aid to understanding, and, again, not todefine the scope or set forth the bounds of the present technology.These modifications are not an exhaustive list, and, as a person skilledin the art would understand, other modifications are likely possible.Further, where this has not been done (i.e., where no examples ofmodifications have been set forth), it should not be interpreted that nomodifications are possible and/or that what is described is the solemanner of implementing that element of the present technology. As aperson skilled in the art would understand, this is likely not the case.In addition, it is to be understood that the system 500 may provide incertain instances simple implementations of the present technology, andthat where such is the case they have been presented in this manner asan aid to understanding. As persons skilled in the art would understand,various implementations of the present technology may be of a greatercomplexity.

In certain non-limiting embodiments of the present technology, thesystem 500 of

FIG. 5 comprises a computer system 510. The computer system 510 isconfigured, by pre-stored program instructions, to determine therotation center 406, based on image data associated with the subject,according to the non-limiting embodiments of the present technology.

To that end, in some non-limiting embodiments of the present technology,the computer system 510 is configured to receive image data pertainingto the subject or to a given orthodontic treatment (such as the 3D model100 depicted in FIG. 1). The computer system 510 may use the image datafor determining the rotation center 406 of the subject. According tosome non-limiting embodiments of the present technology, the computersystem 510 may receive the image data via local input/output interface(such as USB, as an example). In other non-limiting embodiments of thepresent technology, the computer system 510 may be configured to receivethe image data over a communication network 525, to which the computersystem 510 is communicatively coupled.

In some non-limiting embodiments of the present technology, thecommunication network 525 is the Internet and/or an Intranet. Multipleembodiments of the communication network may be envisioned and willbecome apparent to the person skilled in the art of the presenttechnology. Further, how a communication link between the computersystem 510 and the communication network 525 is implemented will depend,inter alia, on how the computer system 510 is implemented, and mayinclude, but are not limited to, a wire-based communication link and awireless communication link (such as a Wi-Fi communication network link,a 3G/4G communication network link, and the like).

It should be noted that the computer system 510 can be configured forreceiving the image data from a vast range of devices (including a CBCTscanner, an intraoral scanner, a laboratory scanner, and the like). Somesuch devices can be used for capturing and/or processing data pertainingto maxillofacial and/or cranial anatomy of a subject. In certainembodiments, the image data received from such devices is indicative ofproperties of anatomical structures of the subject, including: teeth,intraoral mucosa, maxilla, mandible, temporomandibular joint, and nervepathways, among other structures. In some embodiments, at least some ofthe image data is indicative of properties of external portions of theanatomical structures, for example dimensions of a gingival sulcus, anddimensions of an external portion of a tooth (e.g., a crown of thetooth) extending outwardly of the gingival sulcus. In some embodiments,the image data is indicative of properties of internal portions of theanatomical structures, for example volumetric properties of bonesurrounding an internal portion of the tooth (e.g., a root of the tooth)extending inwardly of the gingival sulcus. Under certain circumstances,such volumetric properties may be indicative of periodontal anomalieswhich may be factored into an orthodontic treatment plan. In someembodiments, the image data includes cephalometric image datasets. Insome embodiments, the image data includes datasets generally intendedfor the practice of endodontics. In some embodiments, the image dataincludes datasets generally intended for the practice of periodontics.

The image data may include two-dimensional (2D) data and/ortridimensional data (3D). In certain embodiments, the image dataincludes at least one dataset derived from one or more of the followingimaging modalities: computed tomography (CT), radiography, magneticresonance imaging, ultrasound imaging, nuclear imaging and opticalimaging. Any medical imaging modality is included within the scope ofthe present technology. In certain embodiments, the image data includes2D data, from which 3D data may be derived, and vice versa.

Further, it is contemplated that the computer system 510 may beconfigured for processing of the received image data. The resultingimage data received by the computer system 510 is typically structuredas a binary file or an ASCII file, may be discretized in various ways(e.g., point clouds, polygonal meshes, pixels, voxels, implicitlydefined geometric shapes), and may be formatted in a vast range of fileformats (e.g., STL, OBJ, PLY, DICOM, and various software-specific,proprietary formats). Any image data file format is included within thescope of the present technology. For implementing functions describedabove, the computer system 510 may further comprise a correspondingcomputing environment.

With reference to FIG. 6, there is depicted a schematic diagram of acomputing environment 640 suitable for use with some implementations ofthe present technology. The computing environment 640 comprises varioushardware components including one or more single or multi-coreprocessors collectively represented by a processor 650, a solid-statedrive 660, a random access memory 670 and an input/output interface 680.Communication between the various components of the computingenvironment 640 may be enabled by one or more internal and/or externalbuses 690 (e.g. a PCI bus, universal serial bus, IEEE 1394 “Firewire”bus, SCSI bus, Serial-ATA bus, ARINC bus, etc.), to which the varioushardware components are electronically coupled.

The input/output interface 680 allows enabling networking capabilitiessuch as wire or wireless access. As an example, the input/outputinterface 680 comprises a networking interface such as, but not limitedto, a network port, a network socket, a network interface controller andthe like. Multiple examples of how the networking interface may beimplemented will become apparent to the person skilled in the art of thepresent technology. For example, but without being limiting, theinput/output interface 680 may implement specific physical layer anddata link layer standard such as Ethernet™, Fibre Channel, Wi-Fi™ orToken Ring. The specific physical layer and the data link layer mayprovide a base for a full network protocol stack, allowing communicationamong small groups of computers on the same local area network (LAN) andlarge-scale network communications through routable protocols, such asInternet Protocol (IP).

According to implementations of the present technology, the solid-statedrive 660 stores program instructions suitable for being loaded into therandom access memory 670 and executed by the processor 650, according tocertain aspects and embodiments of the present technology. For example,the program instructions may be part of a library or an application.

In these embodiments, the computing environment 640 is implemented in ageneric computer system which is a conventional computer (i.e. an “offthe shelf” generic computer system). The generic computer system may bea desktop computer/personal computer, but may also be any other type ofelectronic device such as, but not limited to, a laptop, a mobiledevice, a smart phone, a tablet device, or a server.

As persons skilled in the art of the present technology may appreciate,multiple variations as to how the computing environment 640 isimplemented may be envisioned without departing from the scope of thepresent technology.

Referring back to FIG. 5, the computer system 510 has at least oneinterface device 520 for providing an input or an output to a user ofthe system 500, the interface device 520 being in communication with theinput/output interface 680. In the embodiment of FIG. 5, the interfacedevice is a screen 522. In other embodiments, the interface device 520may be a monitor, a speaker, a printer or any other device for providingan output in any form such as image-form, written form, printed form,verbal form, 3D model form, or the like.

In the embodiment of FIG. 5, the interface device 520 also comprises akeyboard 524 and a mouse 526 for receiving input from the user of thesystem 500. Other interface devices 520 for providing an input to thecomputer system 510 can include, without limitation, a USB port, amicrophone, a camera or the like.

The computer system 510 may be connected to other users, such as throughtheir respective clinics, through a server (not depicted). The computersystem 510 may also be connected to stock management or client softwarewhich could be updated with stock when the orthodontic treatment hasbeen determined and/or schedule appointments or follow-ups with clients,for example.

Determining Rotation Center

As alluded to above, according to the non-limiting embodiments of thepresent technology, the rotation center 406 of the mandible 204associated with the subject may be determined by the processor 650 ofthe computing environment 640. To that end, first, the processor 650 maybe configured to receive image data associated with the skull 200.

With reference to FIG. 7, there is depicted a schematic diagram of alateral image 700 of a first side of the skull 200 used, by theprocessor 650, for determining the rotation center 406, in accordancewith the non-limiting embodiments of the present technology.

In the non-limiting embodiments of the present technology, the processor650 has been configured to generate the lateral image 700 based on thereceived image data associated with the skull 200.

In some non-limiting embodiments of the present technology, the imagedata associated with the skull 200 may comprise a 3D image of the skull200, such as a CT scan, and/or a magnetic resonance scan. In othernon-limiting embodiments of the present technology, the image dataassociated with the skull 200 may comprise a 2D image, for example, butnot limited to, a radiograph and/or a photograph.

In specific non-limiting embodiments of the present technology, theradiograph may further comprise a teleroentgenogram (TRG), whichprovides a lateral image of one of the first side and a second side (notseparately depicted) of the skull 200.

Further, in order to determine the rotation center 406, the processor650 may be configured to identify, using the lateral image 700, certainreference points on the skull 200.

To that end, according to the non-limiting embodiments of the presenttechnology, the processor 650 may be configured to determine therotation center 406 as an intersection of reference lines, in thelateral image 700, having been generated based on the identifiedreference points on the skull 200.

In the non-limiting embodiments of the present technology, the processor650 is configured to identify, in the lateral image 700, at least twopairs of reference points to generate, based on each pair of referencepoints, a respective reference line.

In some non-limiting embodiments of the present technology, theprocessor 650 may be configured to identify, for a first pair ofreference points, a first reference point 702 and a second referencepoint 704. According to some non-limiting embodiments of the presenttechnology, the processor 650 is configured to identify the firstreference point 702 to be located on the cranial portion 201 of theskull 200, and the second reference point 704—to be located on themandible 204 of the skull 200. Accordingly, the processor 650 may befurther configured to generate, in the lateral image 700, a firstreference line 710 as a line extending through the first reference point702 and the second reference point 704.

In specific non-limiting embodiments of the present technology, as thefirst reference point 702, the processor 650 may be configured toidentify the Articulare point associated with the skull 200; and as thesecond reference point 704, the processor 650 may be configured toidentify the Gnathion point associated with the skull 200. Thus,according to these embodiments, the first pair of reference points forgenerating the first reference line 710 may include the Articulare pointand the Gnathion point associated with the skull 200.

Further, in some non-limiting embodiments of the present technology, theprocessor 650 may be configured to identify a second pair of referencepoints including a third reference point 706 and a fourth referencepoint 708 for generating a second reference line 712.

According to some non-limiting embodiments of the present technology,the processor 650 is configured to identify the third reference point706 and the fourth reference point 708 as points, which are both locatedon the cranial portion 201 of the skull 200.

In specific non-limiting embodiments of the present technology, as thethird reference point 706, the processor 650 may be configured toidentify the Basion point associated with the skull 200; and as thefourth reference point 708, the processor 650 may be configured toidentify the Orbitale point associated with the skull 200. Thus,according to these embodiments, the second pair of reference points forgenerating the second reference line 712 may include the Basion pointand the Orbitale point associated with the skull 200.

It should be expressly understood that approaches to identifying thefirst reference point 702, the second reference point 704, the thirdreference point 706, and the fourth reference point 708 are not limitedand may include, according to some non-limiting embodiments of thepresent technology, conducting, by the processor 650, a cephalometricanalysis of the image data used for generating the lateral image 700 ofthe skull 200.

Broadly speaking, the cephalometric analysis, as referred to herein, isan analysis including tracing of dental and skeletal relationships(absolute/relative angles and distances) based on certain anatomicalreference points (such as such as the first reference point 702, thesecond reference point 704, the third reference point 706, and thefourth reference point 708) in bony and soft tissue of a skull (forexample, the skull 200). As such, a particular type of the cephalometricanalysis of the skull 200 may depend on the image data, associated withthe skull 200, having been used, by the processor 650, for generatingthe lateral image 700.

For example, in those embodiments where the image data associated withthe skull 200 is represented by 2D images, for example, aposteroanterior radiograph of the skull 200, the cephalometric analysismay comprise a posteroanterior cephalometric analysis. By the sametoken, if the image data associated with the skull 200 comprises alateral radiograph (such as the TRG), the cephalometric analysis maycomprise a lateral cephalometric analysis. In yet another example, wherethe image data associated with the skull 200 is a 3D image thereof (suchas a CT scan or a magnet resonance scan), the cephalometric analysiscomprises a 3D cephalometric analysis.

Further, according to the non-limiting embodiments of the presenttechnology, the conducting, by the processor 650, the cephalometricanalysis may comprise at least (1) segmenting the image data, forexample, into a set of contours, within each of which pixels of theimage data have similar characteristics (that is, computed properties),such as color, intensity, texture, and the like; (2) placing each of theset of contours into a signal coordinate system, thereby aligning eachof the set of contours relative to each other; and (3) detecting thereference points based on predetermined relative positions and distancesthereamong. For example, the Basion point, within the skull 200, may beidentified, by the processor 650, based on a premise that it is a mostanterior point on the foramen magnum (not separately depicted) of theskull 200.

Accordingly, in some non-limiting embodiments of the present technology,for detecting each of the first and the second pairs of referencepoints, the processor 650 may apply an image filtering approach based onenhancing contrast of radiographic images, and further be configured forlocating the reference points therein based on the predeterminedrelative positions and distances thereamong.

In other non-limiting embodiments of the present technology, theprocessor 650 may be configured to apply a model-based approach for thedetecting the reference points. In these embodiments, the processor 650may be configured to apply, to the segmented image data associated withthe skull 200, techniques, such as, but not limited to, pattern matchingtechniques, spatial spectroscopy techniques, statistical patternrecognition techniques, and the like.

In yet other non-limiting embodiments of the present technology, thedetecting the reference points may comprise applying, by the processor650, one or more machine-learning algorithms, such as, but not limitedto, a pulsed coupled neural networks, support vector machines, and thelike. In these embodiments, a given machine-learning algorithm is firsttrained based on a training set of data preliminarily annotated(labelled), for example, by human assessors, for further identifyingspecific reference points based on certain image data associated withthe skull 200. It can be said that, in these embodiments, thepredetermined relative positions and distances among the referencepoints are learnt, by the processor 650, based on the training set ofdata including various image data associated with different skulls.Unsupervised implementations (that is, those not including labellingdata in the training set of data) of machine-learning algorithms mayalso be applied, by the processor 650, without departing from the scopeof the present technology.

Thus, having identified the first reference point 702, the secondreference point 704, the third reference point 706, and the fourthreference point 708, and, based thereon, generated the first referenceline 710 and the second reference line 712, the processor 650 is furtherconfigured to determine the rotation center 406 as an intersectionthereof as depicted in FIG. 7.

As it can be appreciated from FIG. 7, the so determined rotation center406 of the mandible 204 is located in the mandibular head 206, in thelateral image 700, lower and more posteriorly relative to the geometriccenter 306 of the mandibular head 206.

Determining Orthodontic Treatment

According to the non-limiting embodiments of the present technology, theprocessor 650 may further be configured to determine, based on therotation center 406, the orthodontic treatment for the subject. To thatend, the processor 650 may be configured, based at least on the rotationcenter 406 and the 3D model 100, to reproduce a model of the mandible204 of the skull 200 for further determining a rotation axis thereof.Further, the processor 650 may be configured to use the rotation axisfor reproducing at least some of the movements of the mandible 204described above with respect to FIGS. 2 to 4.

With reference to FIG. 8, there is depicted a mandible model 800 of themandible 204 having been generated, by the processor 650, based at leaston the representation lower arch form 104 of the subject and therotation center 406 of the mandible 204, in accordance with thenon-limiting embodiments of the present technology.

As can be appreciated from FIG. 8, the mandible model 800 includes amandible model body 802 having been generated, by the processor 650,based on the 3D model of the lower arch form 104 of the subject; a firstmandible model ramus 804 including a first mandibular head model 808 ofthe mandibular head 206; and a second mandible model ramus 806 includinga second mandibular head model 810.

In some non-limiting embodiments of the present technology, theprocessor 650 has been configured to generate the first mandible modelramus 804 including the first mandibular head model 808 based on therotation center 406. Further, the processor 650 may be configured togenerate, based on the rotation center 406, a rotation axis 814.

In some non-limiting embodiments of the present technology, theprocessor 650 may be configured to generate the rotation axis 814 forthe mandible model 800 to extend through the rotation center 406 andparallel to the horizontal plane 308 associated with the skull 200 (notseparately depicted).

In other non-limiting embodiments of the present technology, theprocessor 650 may be configured to generate the rotation axis 814 forthe mandible model 800 based on the rotation center 406 and a secondrotation center 812. To that end, the processor 650 may have beenconfigured to generate a lateral image of a second side of the skull 200and determine the second rotation center 812 according to thedescription above given in respect of FIG. 7.

Accordingly, based on the second rotation center 812, the processor 650may have been configured to generate the second mandible model ramus 806including the second mandibular head model 810. Finally, the processor650 may be configured to generate the rotation axis 814 for the mandiblemodel 800 as a line extending through the rotation center 406 and thesecond rotation center 812 in the first mandibular head model 808 andthe second mandibular head model 810, respectively.

Thus, referring back to FIG. 1 and with continued reference to FIG. 8,according to the non-limiting embodiments of the present technology,based on the so generated mandible model 800 including the rotation axis814, the processor 650 may be further configured to reproduce at leastsome of the movements of the mandible 204 indicative of the articulationthereof, as discussed above with reference to FIGS. 2 to 4, on the 3Dmodel 100, specifically, movements of the lower arch form 104 relativeto the upper arch form 102.

For example, the processor 650 may reproduce simultaneous translationaland rotational movements of the lower arch form 104, as described withreference to FIG. 4 in respect of the mandible 204. Specifically, whenthe first mandibular head model 808 is moving around the rotation axis814 rotationally clockwise in a first direction 816 and translationallyforward in a second direction 818, the lower arch form 104 will bemoving rotationally counterclockwise in a third direction 820 andtranslationally backwards in a fourth direction 822. Also, as previouslymentioned, based on these movements, certain diagnostic parameters fordevising the orthodontic treatment can be considered.

Given the architecture and the examples provided hereinabove, it ispossible to execute a method for determining an orthodontic treatmentfor a subject. With reference to FIG. 9, there is depicted a flowchartof a method 900, according to the non-limiting embodiments of thepresent technology. The method 900 can be executed by a processor of acomputing environment, such as the processor 650 of the computingenvironment 640.

According to the non-limiting embodiments of the present technology, theprocessor 650 is configured to determine the orthodontic treatment basedon a rotation center of a subject's mandibular jaw (for example, therotation center 406 of the mandible 204 as described above withreference to FIG. 4).

STEP 902—RECEIVING IMAGE DATA ASSOCIATED WITH AN IMAGE OF A SKULL OF THEPATIENT, THE IMAGE DATA INCLUDING DATA RELATING TO A MANDIBULAR PORTIONAND A CRANIUM PORTION OF THE SKULL

The method 900 commences at step 902 where the processor 650 isconfigured to receive image data associated with a subject's skull (suchas the skull 200 depicted in FIGS. 2 to 4).

In the non-limiting embodiments of the present technology, the processor650 may be configured to receive a 3D image of the skull 200, such as aCT scan, and/or a magnetic resonance scan. In other non-limitingembodiments of the present technology, the image data associated withthe skull 200 may comprise a 2D image, for example, but not limited to,a radiograph and/or a photograph.

In specific non-limiting embodiments of the present technology, theradiograph may further comprise a teleroentgenogram (TRG).

Further, according to the non-limiting embodiments of the presenttechnology, the processor 650 can be configured to generate, based onthe received image data, a lateral image of at least one of the firstand the second sides of the skull 200 (such as the lateral image 700depicted in FIG. 7 and described with reference thereto).

According to the non-limiting embodiments of the present technology, thelateral image 700 is further used, by the processor 650, for identifyingspecific reference points associated with the skull 200. Based on theidentified reference points, the processor 650 may further be configuredto determine the rotation center 406 of the mandible 204.

The method 900 hence advances to step 904.

STEP 904—IDENTIFYING, FROM THE IMAGE DATA, A FIRST PAIR OF REFERENCEPOINTS FOR DEFINING A FIRST REFERENCE LINE, THE FIRST PAIR OF REFERENCEPOINTS INCLUDING A FIRST POINT ON THE MANDIBULAR PORTION AND A SECONDPOINT ON THE CRANIUM PORTION OF THE SKULL OF THE PATIENT

At step 904, the processor 650 is configured, using the lateral image700, to identify a first pair of reference points, for example, thefirst reference point 702 and the second reference point 704 asdescribed above with reference to FIG. 7.

According to the non-limiting embodiments of the present technology, theprocessor 650 is configured to identify the first reference point 702 asa point located on the cranial portion 201 of the skull 200; andidentify the second reference point 704 as a point located on themandible 204.

In specific non-limiting embodiments of the present technology, as thefirst reference point 702, the processor 650 can be configured toidentify the Articulare point associated with the skull 200; and as thesecond reference point 704, the processor 650 can be configured toidentify the Gnathion point associated with the skull 200.

According to the non-limiting embodiments of the present technology, inorder to identify the reference points (such as the first referencepoint 702 and the second reference point 704), the processor 650 may beconfigured to conduct a cephalometric analysis of the image data usedfor generating the lateral image 700. In certain non-limitingembodiments of the present technology, the processor 650 may beconfigured to conduct the cephalometric analysis of the lateral image700.

As described above with reference to FIG. 7, the cephalometric analysisallows for automatically tracing of dental and skeletal relationships(absolute/relative angles and distances) based on certain anatomicalreference points in bony and soft tissue of the skull 200.

According to the non-limiting embodiments of the present technology, theconducting, by the processor 650, the cephalometric analysis cancomprise at least (1) segmenting the image data, for example, into a setof contours, within each of which pixels of the image data have similarcharacteristics (such as color, intensity, texture, and the like); (2)placing each of the set of contours into a signal coordinate system,thereby aligning each of the set of contours relative to each other; and(3) detecting the reference points based on predetermined relativepositions and distances thereamong.

According to the non-limiting embodiments of the present technology, fordetecting the reference points associated with the skull 200, theprocessor 650 can be configured to apply at least one of an imagefiltering approach, a model-based approach, and a machine-learningapproach, as described above with reference to FIG. 7.

Having determined the first pair of reference points, the method 900advances to step 906.

STEP 906—IDENTIFYING, FROM THE IMAGE DATA, A SECOND PAIR OF REFERENCEPOINTS FOR DEFINING A SECOND REFERENCE LINE, THE SECOND PAIR OFREFERENCE POINTS INCLUDING A THIRD AND FOURTH POINTS ON THE CRANIUMPORTION OF THE SKULL; THE SECOND REFERENCE LINE INTERSECTING WITH THEFIRST REFERENCE LINE

At step 906, via conducting the cephalometric analysis as describedabove, the processor 650 is configured to identify a second pair ofreference points. For example, the processor 650 may be configured toidentify the third reference point 706 and the fourth reference point708. According to the non-limiting embodiments of the presenttechnology, the processor 650 may be configured identify the thirdreference point 706 and the fourth reference point 708 both to belocated on the mandible 204.

In specific non-limiting embodiments of the present technology, as thethird reference point 706, the processor 650 may be configured toidentify the Basion point associated with the skull 200; and as thefourth reference point 708, the processor 650 may be configured toidentify the Orbitale point associated with the skull 200.

Having determined the second pair of reference points, the method 900advances to step 906.

STEP 908—GENERATING, BASED ON THE FIRST PAIR OF REFERENCE POINTS, THEFIRST REFERENCE LINE

According to the non-limiting embodiments of the present technology, inorder to determine the rotation center 406, the processor 650 isconfigured to generate reference lines based on the so identifiedreference points. Thus, at step 908, the processor 650 is configured togenerate, based on the first pair of reference points (that is, thefirst reference point 702 and the reference point 704), the firstreference line 710, as described above with reference to FIG. 7.

Thus, in specific non-limiting embodiments of the present technology,the first reference line 710 is extending through the Articulare pointand the Gnathion point associated with the skull 200.

STEP 910—GENERATING, BASED ON THE SECOND PAIR OF REFERENCE POINTS, THESECOND REFERENCE LINE

At step 910, the processor 650 is configured to generate a secondreference line, based on the second pair of reference points, which arethe third reference point 706 and the fourth reference point 708. Forexample, the processor 650 can be configured to generate the secondreference line 712, as described above with reference to FIG. 7.

Thus, in specific non-limiting embodiments of the present technology,the second reference line 712 is extending through the Basion point andthe Orbitale point associated with the skull 200.

Having generated the first reference line 710 and the second referenceline 712, the method 900 advances to step 912.

STEP 912—DETERMINING, BASED ON AN INTERSECTION OF THE FIRST REFERENCELINE AND THE SECOND REFERENCE LINE, A ROTATION CENTER FOR THE PATIENT′SMANDIBLE

At step 912, according to the non-limiting embodiments of the presenttechnology, the processor 650 is configured to determine the rotationcenter 406 of the mandible 204 based on the so generated the firstreference line 710 and the second reference line 712. To that end, theprocessor 650 is configured to determine the rotation center 406 as anintersection of the first reference line 710 and the second referenceline 712, as depicted in FIG. 7.

As can be appreciated from FIG. 7, the so determined rotation center 406is located lower and more posteriorly than the geometric center 306 ofthe mandibular head 206 of the mandible 204.

The method 900 hence advances to step 914.

STEP 914—DETERMINING, BASED ON THE DETERMINED ROTATION CENTER OF THEPATIENT′S MANDIBLE, THE ORTHODONTIC TREATMENT FOR THE PATIENT

At step 914, according to the non-limiting embodiments of the presenttechnology, the processor 650 is configured to determine the orthodontictreatment for the subject based at least on the so determine rotationcenter 406 and a 3D model of subject's arch forms (for example, the 3Dmodel 100 depicted in FIG. 1).

According to the non-limiting embodiments of the present technology, thedetermining the orthodontic treatment for the subject can comprisedetermining, based on the rotation center 406, movements of the lowerarch form 104 relative to the upper arch form 102 of the subject. Inthis regard, the processor 650 may be configured to determine a rotationaxis (such as the rotation axis 814 depicted in FIG. 8) for the lowerarch form 104.

To that end, the processor 650 can be configured to generate a model ofthe mandible 204 of the subject based on the 3D model 100 and therotation center 406—for example the mandible model 800 depicted in FIG.8.

As can be appreciated form FIG. 8, the mandible model 800 comprises themandible model body 802, generated based on the lower arch form 104; andthe first mandible model ramus 804 including the first mandibular headmodel 808 of the mandibular head 206, generated based on the rotationcenter 406. Thus, in some non-limiting embodiments of the presenttechnology, the processor 650 may be configured to determine therotation axis 814 as a line extending through the rotation center 406and being parallel to the horizontal plane 308 of the skull 200.

In other non-limiting embodiments of the present technology, theprocessor 650 may be configured to determine a second rotation center ofthe mandible 204 (for example, the second rotation center 812). To thatend, the processor 650 may be configured, based on the received imagedata associated with the subject, to generate the second lateral imageof the second side (not separately depicted) of the skull 200 and apply,mutatis mutandis, the approach for determining the rotation center 406described above. Further, the processor 650 may be configured, based onthe determined second rotation center 812, to generate the secondmandible model ramus 806 including the second mandibular head model 810.

Thus, the processor 650 may be configured to determine the rotation axis814 as a line extending through the rotation center 406 and the secondrotation center 812 located in the first mandibular head model 808 andthe second mandibular head model 810, respectively.

Accordingly, by doing so, the processor 650 can be said to be configuredto transfer at least some of the articulation movements of the mandible204 described above with reference to FIGS. 2 to 4 onto the lower archform 104 for reproducing its movements relative to the upper arch form102.

Thus, certain embodiments of the method 900 allow for reproducing, basedon the rotation center 406, kinematics of the lower arch form 104 of thesubject which are realistic and effectively account for rotational andtranslational components thereof using only 2D image data, in theabsence of CT or magnetic resonance scans of the skull 200. Further, thepresent technology allows for determining the rotation center 406individually for the subject, based on specifically determined referencepoints associated with the skull 200 as the first reference point 702,the second reference point 704, the third reference point 706, and thefourth reference point 708 may be indicative of muscle attachments ofthe muscles aiding in effectuating the movements of the mandible 204uniquely associated with the subject. Thus, some embodiments of thepresent technology are directed to more efficient methods and systemsfor determining individualized orthodontic treatment.

The method 900 hence terminates.

It should be expressly understood that not all technical effectsmentioned herein need to be enjoyed in each and every embodiment of thepresent technology.

Modifications and improvements to the above-described implementations ofthe present technology may become apparent to those skilled in the art.The foregoing description is intended to be exemplary rather thanlimiting. The scope of the present technology is therefore intended tobe limited solely by the scope of the appended claims.

1. A method for determining an orthodontic treatment for a patient, themethod being executable by a processor, the method comprising: receivingimage data, the image data being associated with an image of a skull ofthe patient, the image data including data relating to a mandibularportion and a cranium portion of the skull; conducting, by theprocessor, based on the image data, a cephalometric analysis of theskull of the patient; identifying, via the cephalometric analysis, afirst pair of anatomical reference points for defining a first referenceline, the first pair of anatomical reference points including a firstpoint on the mandibular portion and a second point on the craniumportion of the skull of the patient; identifying, via the cephalometricanalysis, a second pair of anatomical reference points for defining asecond reference line, the second pair of anatomical reference pointsincluding a third and fourth points on the cranium portion of the skull;the second reference line intersecting with the first reference line;generating, based on the first pair of anatomical reference points, thefirst reference line; generating, based on the second pair of anatomicalreference points, the second reference line; determining, based on anintersection of the first reference line and the second reference line,a rotation center for a patient's mandible; determining, based on therotation center of the patient's mandible, the orthodontic treatment forthe patient.
 2. The method of claim 1, wherein the first point of thefirst pair of anatomical reference points comprises an Articulare point,and the second point of the first pair of anatomical reference pointscomprises a Gnathion point.
 3. The method of claim 1, wherein the thirdpoint of the second pair of anatomical reference points comprises aBasion point, and the fourth point of the second pair of anatomicalreference points comprises an Orbitale point.
 4. The method of claim 1,wherein the first point of the first pair of anatomical reference pointscomprises the Articulare point, the second point of the first pair ofanatomical reference points comprises the Gnathion point, the thirdpoint of the second pair of anatomical reference points comprises theBasion point, and the fourth point of the second pair of anatomicalreference points comprises the Orbitale point.
 5. The method of claim 1,wherein the cephalometric analysis comprises processing the image databased on one or more of: image segmentation, image alignment, faciallandmark detection, and predetermined relative positions betweenanatomical landmarks.
 6. The method of claim 1, wherein the imagecomprises one or more of: a radiograph, a photograph, a CT scan, adental model, and a magnetic resonance image.
 7. The method of claim 1,wherein the image is a lateral image of a first side of the skull of thepatient.
 8. The method of claim 7, wherein the rotation center is afirst rotation center of the first side of the skull of the patient, andwherein the method further comprises determining a second rotationcenter based on an image of a second side of the skull of the patient,and wherein the determining the orthodontic treatment is based on thefirst rotation and the second rotation center.
 9. The method of claim 1,wherein the rotation center is not a center of a mandibular head. 10.The method of claim 1, further comprising sending instructions todisplay, on a screen, the image of at least a portion of the skull andincluding the rotation center of the mandible.
 11. A method forgenerating a visualization of a skull of a patient including a rotationcenter of a mandible, the method being executable by a processor, themethod comprising: receiving image data, the image data being associatedwith an image of the skull of the patient, the image data including datarelating to a mandibular portion and a cranium portion of the skull;conducting, by the processor, based on the image data, a cephalometricanalysis of the skull of the patient; identifying, via cephalometricanalysis, a first pair of anatomical reference points for defining afirst reference line, the first pair of anatomical reference pointsincluding a first point on the mandibular portion and a second point onthe cranium portion of the skull of the patient; identifying, via thecephalometric analysis, a second pair of anatomical reference points fordefining a second reference line, the second pair of anatomicalreference points including a third and fourth points on the craniumportion of the skull; the second reference line intersecting with thefirst reference line; generating, based on the first pair of anatomicalreference points, the first reference line; generating, based on thesecond pair of anatomical reference points, the second reference line;determining, based on an intersection of the first reference line andthe second reference line, a rotation center for a patient's mandible;sending instructions to display, on a screen, the image of the skullincluding the rotation center for the patient's mandible.
 12. A systemfor determining an orthodontic treatment for a patient, the systemcomprising a computer system having a processor arranged to execute amethod comprising: receiving image data, the image data being associatedwith an image of a skull of the patient, the image data including datarelating to a mandibular portion and a cranium portion of the skull;conducting, based on the image data, a cephalometric analysis of theskull of the patient; identifying, via the cephalometric analysis, afirst pair of anatomical reference points for defining a first referenceline, the first pair of anatomical reference points including a firstpoint on the mandibular portion and a second point on the craniumportion of the skull of the patient; identifying, via the cephalometricanalysis, a second pair of anatomical reference points for defining asecond reference line, the second pair of anatomical reference pointsincluding a third and fourth points on the cranium portion of the skull;the second reference line intersecting with the first reference line;generating, based on the first pair of anatomical reference points, thefirst reference line; generating, based on the second pair of anatomicalreference points, the second reference line; determining, based on anintersection of the first reference line and the second reference line,a rotation center for a patient's mandible; determining, based on therotation center of the patient's mandible, the orthodontic treatment forthe patient.
 13. The system of claim 12, wherein the first point of thefirst pair of anatomical reference points comprises an Articulare point,and the second point of the first pair of anatomical reference pointscomprises a Gnathion point.
 14. The system of claim 12, wherein thethird point of the second pair of anatomical reference points comprisesa Basion point, and the fourth point of the second pair of anatomicalreference points comprises an Orbitale point.
 15. The system of claim12, wherein the first point of the first pair of anatomical referencepoints comprises the Articulare point, the second point of the firstpair of anatomical reference points comprises the Gnathion point, thethird point of the second pair of anatomical reference points comprisesthe Basion point, and the fourth point of the second pair of anatomicalreference points comprises the Orbitale point.
 16. The system of claim12, wherein the cephalometric analysis comprises processing the imagedata based on one or more of: image segmentation, image alignment,facial landmark detection, and predetermined relative positions betweenanatomical landmarks.
 17. The system of claim 12, wherein the image is alateral image of a first side of the patient's skull of the patient, andwherein the rotation center is a first rotation center of the first sideof the skull of the patient, and wherein the system further comprisesdetermining a second rotation center based on an image of a second sideof the skull of the patient, and wherein the determining the orthodontictreatment is based on the first rotation and the second rotation center.18. The system of claim 12, wherein the rotation center is not a centerof a mandibular head.
 19. The system of claim 12, wherein the imagecomprises one or more of: a radiograph, a photograph, a CT scan, adental model, and a magnetic resonance image.
 20. The system of claim12, wherein the processor is further configured to send instructions todisplay, on a screen, the image of at least a portion of the skull andincluding the rotation center of the mandible.